Though he began and ended his Senate years as a Democrat, Specter represented the state of Pennsylvania in Congress as a Republican for most of his 5 terms in the highest legislative chamber. His political platform was always moderate centrist, but his party affiliation was born of expediency and rooted in ideological pragmatism. A Jewish pro-choice Republican, Specter was first and foremost a political survivor whose wit and sharp tongue cut whichever way was most electorally prudent.

As a former prosecutor, Specter was at his most compelling when in battle and often took a partisan role, but he was also skilled at walking a narrow line in partisan squabbles he wanted to avoid. His vote of “not proved” gave the body a tie vote and saved President Clinton from impeachment in 1999.

The senator’s enduring drive to win his last electoral contest compelled him in 2009, at nearly 80 years old, to throw in his fortunes with the party he had spent so many years opposing.

Although both political parties have been known to welcome defecting sitting lawmakers to their caucus, Democratic Pennsylvania voters could not forgive Specter for his treatment of Hill or his years of alliance with Pennsylvania’s far more conservative senator, Rick Santorum. The newly Democratic incumbent lost his seat of 30 years in the 2010 primary to Joe Sestak. Sestak was defeated in the general election by Republican Pat Toomey.

Arlen Specter didn’t always make friends, but he always made an impression. Seemingly indomitable, Specter next wrote a second memoir, returned to a private law practice and made occasional appearances at Philadelphia comedy clubs to crack jokes at the expense of Bill Clinton and former Pennsylvania governor Ed Rendell.

The same survivor’s spirit was apparent in Specter’s very public fight against cancer which he twice survived in 2005 and 2008. When learning of a recurrence earlier this year, Specter announced with typical resolve, “It’s another battle I intend to win. I’m grateful for all the well-wishes I’ve received. I’m looking forward to getting back to work, to the comedy stage, to the squash court, and to the ball park.”

Bonnie Goldstein is a writer in Washington, D.C. Follow her on Twitter at @KickedByAnAngel.